Xanthogranulomatous Pyelonephritis (XGP) is an uncommon sequelae of chronic renal inflammation whose process may invade local structures. We present a rare case of an invasive Xanthogranulomatous Pyelonephritis (XGP) extending into the thoracic cavity in a 48 year-old female presenting with chronic productive cough. This previously healthy patient presented with dyspnea, productive cough, and unintentional twenty pounds weight loss over three months. Physical examination demonstrated right costo-phrenic tenderness and diffuse right-sided rhonchi. A chest X-ray showed a right lower lobe opacity with compression of the thoracic cavity. Subsequent computed tomography (CT) demonstrated a right staghorn calculus with a perinephric, perihepatic multiseptated abscess extending through the diaphragm with a large loculated pulmonary abscess involving the right lung.
Urinalysis confirmed the presence of infection with pyruia and bacteriuria. Bronchoscopy showed airway inflammation in the right lobe. She had right chest tube, right nephrostomy bag and right abdominal drains placement. All the drained fluid, including the bronchoalveolar lavage and urine analysis were cultured and resulted in Proteus Mirabilis. She was treated with an extensive course of broad-spectrum antibiotics but eventually required a laproscopic nephrectomy. This renal surgical tissue confirmed XGP on histology. On follow up, she recovered uneventfully.
Discussion:
XGP, is a rare sequela of severe chronic pyelonephritis and seen in 1% of all renal infections often with chronic obstruction from infected nephrolithiasis. Granulomatous destruction of the renal parenchyma by lipid laden macrophages called xanthomas may lead to multi-organ invasion, which usually involves liver, and bowel but can rarely extend into the lung via trans-diaphragmatic seeding. Massive granulomatous destruction leads to renal failure, which can appear as a renal malignancy on CT. In contrast to this patient, XGP typically presents with urinary complaints, and abdominal discomfort. There are only a few reported cases of XGP involving the lung, this is a first known case to cause thoracic compression in a patient without genitourinary complains.
Conclusions:
XGP should be considered in the presence of a large thoracic abscess associated with abdominal mass.